A tennis racket, like other rackets for use in racket sports, e.g. tennis, squash, badminton and racketball, comprises a handle formed with a grip, a shaft connected to the handle and generally extending therefrom to a throat of the racket and a head which is formed with a frame spanned by an openwork which is generally referred to as stringing and can be composed of main strings which run parallel to the axis of the racket and cross strings which run transversely thereto
The strings can be composed of synthetic resin, e.g. nylon, or a natural material and the head can be circular or oval, i.e. generally round. The stringing forms a striking face of the racket and the central zone thereof is generally referred to as the "sweet spot" to indicate that a blow applied to the ball in this region will permit best control of the direction of the ball, most effective transfer of energy to the ball, and least torsion or twist by reaction forces on the racket which may cause discomfiture for the player.
The cords or strings generally pass through the frame body through so-called string holes.
The base of the head located adjacent the throat generally forms a bridge between two shoulders of the frame which are extended toward the free end of the latter which can be referred to as the crown.
While we may refer, in this description, to a tennis racket, it should be understood that this term is intended to include similar rackets for the other racket sports described as well as rackets for other sports which may not have been mentioned but which nevertheless may use a strung racket.
Conventional rackets of the type described have, as a significant disadvantage, the lack of any mean for effectively damping the vibration of the strings resulting from impact with the ball. While the handle and frame of a racket may be designed to minimize the transfer of vibration from the stringing to the hand and arm of the player, the fact remains that the absence of an effective damping device between the stringing and the head or frame of the racket results in a transfer of significant vibrational energy to the head and then through the handle to the arm of the user, regardless of how effective the vibration-damping effect of the handle and shaft may be and regardless of the materials from which the racket body may be constructed to resist the generation of sympathetic vibration and their transfer to the arms of the user.
In addition, the lack of any vibration-damping at the strings themselves results in the generation of disagreeable sounds between the devices generally provided between the frame and the string to permit passage of the string or cord without deterioration thereof. For example, without such protective devices, e.g. in the form of eyelets or tubular string protectors, a string passing through a tubular bridge or frame part of the racket may be subjected to considerable stress at the edge of the string hole which can cause wear of the string or a slicing action even after relatively limited use.
Thus while such protective means may be essential for at least certain types of racket, the very existence of such means results in the generation of noise upon impact of the stringing with the ball which is a drawback as mentioned above.